Desynchronization of rhythms activity (DNA-SA) and/or in mitotic index (MI) between normal and neoplastic cell populations within the same animal is being attempted. Isoproterenol (IPR), Cyclophosphamide (CTX), Hydroxyurea (HU) and 5-fluorouracil (FU) are examples of drugs which significantly alter the rhythmic profiles of DNA-Sa and/or MI in normals tissues (epithelium of the tongue, cornea and rectum) when treatment occurs at 0500 hours. These same drugs, in general, have very little effect on the rhythms when given at 1700 hours. It has been possible to induce maximal DNa-Sa and/or MI activity in the Ehrlich Ascites Carcinoma (EAC) at a point in time when DNA-SA and/or MI activity are at minimal levels in several normal tissues in the same animals. The overall goal of this research project is to translate these induced differences in DNA-SA or MI activity between normal and neoplastic cell populations to therapeutic advantage.